So what horsepower level are people needing to upgrade the injectors/pump?
 

Simple enough question, trying to plan for the future

Thanks

If you boost, it's pretty safe to just buy upgraded injectors. I'm gonna be running 700cc injectors on a 400HP+ setup...but that's just what was reccomended by the shop building my kit.

It is not very likely that you will need to upgrade them if you stay NA, unless you do an E85 tune. If you go with forced induction then you will definitely need to upgrade both.

-Zach

So ok, to be more specific...

1- this is the forced induction forum ;) - So assumed forced induction
2- I ask because companies like AVO are making 230-250whp on stock injectors and while I like their kit, I know I will want more power shortly after... I'd like to know when I'd need to plan for injectors, so I can budget for the upgrades to happen all together and not have issues.

Thanks guys

Well everyone seems to be ok with 550cc injectors for sub 350HP, I think a few have taken them up past 400HP so they work there. I went 700cc to give me more room to go even higher than 400HP once theres a few more options to reduce compression. I may be wrong here but I am under the impression that you can run a higher flow rate injector for lower power figures, it's all about duty cycles etc. So for future proofing I don't think it hurst to go bigger. I'm sure that if i am wrong someone will chime in!

I'm aware you can always go big on injectors (and its smart to because usually a 900cc set and 400cc set are the same cost), however I was just curious where the stock FA20 ones are beyond 90% duty cycle (as I don't like going much higher than that). But this is good info as other might ask this question. :)

Thanks for the help so far... Anyone else have insight on the stock injector limit?

Here check out this thread, on page 16 Visconti suggests that anything over 6PSI of boost should have upgraded injectors, he also says on the same page that 550cc injectors are easier to tune for 400ish HP.

http://www.ft86club.com/forums/showt...jector&page=16

Curious as to the specs (snail size, location) you are going with to reach that number (we have similar goals) and what shop in Phoenix have you commissioned for the work? Sorry for the thread jack, don't hang me, my PM system isn't working ATM.

I'm getting mine through P&L Motorsports, definitely not in PHX though!

Thanks sir.
I'll take a look thru that thread! :thumbup:

In our testing on the car in Japan, we ran out of injector (90% duty cycle) at roughly 280whp on 94 octane gas, 6.5 psi.

I have STI Pink Injectors lying around, 550cc from memory...might use these if i get the AVO kit

I'm surprised at this, primarily because I don't experience with FI with DI but I had it in my mind that DI injectors with their high pressure fuel pump running at 30-50,000 PSI would be able to insert enough fuel.

My expectation is clearly wrong and it would appear that the fact that the fuel is being squirted by DI or that the HPFP is at a very high PSI isn't as important as the size of the squirter itself (to use unscientific terms).

Good to know as I plan on going FI in the future for race trim and will probably be a bit above 6 psi.

Thanks Paul



Anyone able to chime in on the pump?